Plating, Chemical Plating Technique Using Partial Chemicaloxidation for Aluminum or Aluminum Copper Radiator

ABSTRACT

This invention involves the technological area of plating, chemical electrodeposit of aluminum and aluminum copper radiator, referring specifically to some electrodeposit and chemical electrodeposit techniques of the partial chemical oxidation in aluminum and aluminum copper radiator. This invention is to conduct partial chemical oxidation and enclosure to the radiator before it undergoes the galvanization. It has to oxidize the non surfacing with chemical oxidation and cover a layer of porous film, and then utilize the sealing compound to fill up the holes of porous film, which makes the porous film form a layer of film against the erosion of acid and alkali, and connect the current existing chemical electrodeposit or electrodeposit techniques, only electrodeposit a wieldable nickel-phosphorus alloy in the connected part where the aluminum radiator or the aluminums and copper radiator with the main frame. This invention&#39;s technique only applies the chemical electrodeposit or electrodeposit to the surface that need electrodeposit in the radiator, which is simple and easy to be implemented, saving the expensive metal resource and reducing the product costs.

CROSS REFERENCE TO THE RELATED PATENT APPLICATION

This application claims the priority of the Chinese patent application No. 200710028893.0 with filing date of Jul. 3, 2007.

FILED OF THE INVENTION

This invention involves the technological area of plating, chemical electrodeposit techniques to aluminum and aluminum copper radiator, referring specifically to plating, chemical-plating techniques of partial oxidation to aluminum and aluminum copper radiators.

BACKGROUND OF THE INVENTION

The stacking of aluminum sheet that is processed by machines forms aluminum radiator, while the aluminum copper radiator is formed by the copper heat pipes tightly plugging in the aluminum radiator. Since the weldability of aluminum is poor, it is necessary to plate a layer of weldable alloy of nickel-phosphorus in the location where the aluminum or aluminum copper radiator connects with the main frame so that the above aluminum radiator or aluminum copper radiators can connect with the main frame that need heat radiating so as to weld the two together.

On the aluminum surface, it is easy to form the natural film, which is not good for the electrodeposit or chemical plating of aluminum. For the electrodeposit or chemical plating on the aluminum surface, there should be a preplating process for the aluminum to be plated. The current regular preplating is the double galvanization technique. See the attached pic 1 of the current ordinary chemical plating of nickel-phosphorus alloy. The procedures are as brief as the following:

Step 1: degreasing, removing the oil stain on the radiator surface.

Step 2: water rinsing, cleaning the radiator

Step 3: weak erosion, putting the radiator in the lye and conducting weak erosion on the radiator surface.

Step 4: water rinsing, cleaning the radiator

Step 5: exposure to light, putting the radiator in the acid liquor and exposing it to light.

Step 6: water rinsing, cleaning the radiator;

Step 7: the first galvanization, putting the radiator in the lye containing the zincates for the first galvanization.

Step 8: water rinsing, cleaning the radiator

Step 9: removing the zinc, putting the radiator in the acid liquor for zinc removal.

Step 10: water rinsing, cleaning the radiator;

Step 11: the second galvanization, putting the radiator in the lye with zincates for the second galvanization;

Water rinsing, cleaning the radiator;

Step 13: electrodeposit the nickel and phosphor alloy, putting the radiator in the chemical electrodeposit trough of nickel and electrodeposit the nickel and phosphor on the radiator surface.

Water rinsing, cleaning the radiator;

Step 15: drying

Step 16: parching

Step 17: finished products

The above process flow can be simplified as: preplating 1, galvanization 2, electrodeposit nickel-phosphorus alloy, post-treatment, 3. Finished products.

After the radiator is chemical plated with nickel-phosphorus alloy or plated, the whole aluminum or aluminum copper radiator is plated with nickel-phosphorus alloy, including the welding section and the non-welding section of the radiator; the non-welding section of the radiator does not need plating. The costs for nickel and phosphor alloy are high, causing the price of aluminum or aluminum copper radiators stay high as always.

SUMMARY OF THE INVENTION

The purpose of this invention aims to provide some plating, chemical electrodeposit technique for partial chemical oxidation of the aluminum and aluminum copper radiator regarding to the deficiency of above techniques. This technique only applies chemical electrodeposit or electrodeposit to a section of the radiator that needs plating, which is simple and easy for implementation, saving nickel and effectively reducing the product costs.

To achieve the aforesaid goal, Some kind of plating, chemical plating techniques for the partial chemical oxidation of aluminum and aluminum and copper radiator with characteristics including the following procedures:

Step 1: pretreatment to the radiator, then applying degreasing, water rinsing, weak erosion (conducting the weak erosion with lye, water rinsing, exposure to light bywashing with acid), water rinsing;

Step 2: partial chemical oxidation. During partial chemical oxidization, put the section that need not plating, part of the aluminum and aluminum copper radiator into oxidization trough containing the solutions with oxidant. The section needing plating is above the trough surface to avoid oxidization. After the part is oxidized, the aluminum or aluminum copper radiator surface is covered with a colorless porous film.

Step 3: water rinsing

Step 4: enclosure (filled up), putting the whole radiator in the enclosed trench with water solution containing sealing compound; after the radiator is enclosed, the holes of the porous film on the radiator surface is filled up with sealing compound; on the radiator surface there is a film against the erosion of acid and alkali.

Step 5: water rinsing

Step 6: weak erosion; putting the whole radiator in the lye and conducting partial weak erosion to the section that need electrodeposit in the radiator.

Step 7: water rinsing

Step 8: exposure to light (acid liquor)

Step 9: water rinsing

Step 10: galvanization, conducting galvanization, water rinsing, zinc removal (acid cleaning), second galvanization, water rinsing to the radiator one by one.

Step 11: electrodeposits nickel-phosphorus alloy, conducting chemical plating or electrodeposits the radiator, the only section not covered by porous film being plated with nickel-phosphorus alloy.

Step 12: post-treatment, then conducting water rinsing, drying and parching to the radiator.

Step 13: finished product.

As shown in the above technical plan, the applicant developed the partial plating technique to save some precious metal such as nickel. This invention is to conduct partial chemical oxidization and enclosure before the galvanization process of the radiators. First, the non-plating section is oxidized through partial oxidization and covered with a layer of porous film. Then the holes in the porous film are filled up with sealing compound through enclosure, which forms a film against the acid and alkali. Then it follows the existing chemical plating or electrodeposit process. In the subsequent processes, this porous film will not accumulate the zinc nor will it be plated with nickel-phosphorus alloy. The wieldable nickel-phosphorus alloy is only plated in the location where the aluminum or aluminum copper radiator is connected with the mainframe. This technique applies partial plating to the aluminum or aluminum copper radiators needing plating, thus called partial plating. The core technology in the partial chemical oxidization and enclosure of the invention can also be applied to electro-coppering, nickel-plating layer or chemical coppering, which is the corresponding processes of electro-coppering, electro-nickel plating or chemical copper plating after the second galvanization. This achieves the partial electoral coppering, electro-nickel plating or chemical copper plating in the aluminum or aluminum copper radiators. It saves various expensive metals and reduces the costs. To sum up, this invention applies the partial chemical plating or electrodeposits to the sections needing plating in the radiators. The process is simple and easy to be carried out. It can save the metals such as nickel and reduce the costs.

BRIEF DESCRIPTION OF THE DRAWINGS

Attached Pic 1: Technical Process Flow of the current nickel-electrodeposit of current radiators.

Attached Pic 2: the technical process flow of this invention.

DETAIL DESCRIPTION OF THE INVENTION

To further unveil this invention, the following will give the illustration together with attach Pic 2, including the following procedures:

Step 1: conducting preplating to the radiator, then continue with degreasing, water rinsing, weak erosion (with lye), water rinsing, exposure to light (with acid), water rinsing; each procedure for the preplating in this invention is the same as the current process technique in the current pre-treatment.

Step 2: partial chemical oxidation. During partial chemical oxidization, put the section that need not plating, part of the aluminum and aluminum copper radiator into oxidization trough containing the solutions with oxidant. The section needing plating is above the trough surface to avoid oxidization. The mentioned oxidants are organic amine, which are trolamine or formamine. After the partial chemical oxidization, the aluminum or aluminum copper radiators' surface that is under the trough surface is covered with a layer of colorless porous film.

The solution temperature is 80-95° C.; the time for oxidization is 8-30 min. the thickness of the porous film after oxidization is 0.5-5 micron.

Step 3: water rinsing, cleaning the radiator

Step 4: enclosure (filled up), putting the radiator in the enclosed trough with water solution containing sealing compound; the mentioned sealing compound is boric acid; after the radiator is enclosed, the holes of porous film on the radiator surface is filled up with the sealing compound in the enclosed trough. A film is formed on the radiator surface that is against the erosion of acid and alkali. Here, the temperature of water solution containing sealing compound is around 85-95° C. and the enclosure time is 8-30 min.

The porous film formed on the radiator surface in Step 2 cannot withstand the erosion of acid and alkali, so the base of aluminum or aluminum copper radiator will segment with a layer of zinc due to the erosion of alkali in the zincates. Thus, the aluminum or aluminum copper radiator covered with a layer of zinc can be plated with nickel and phosphor alloy in the trough of chemical plating with nickel. The holes in this porous film should be filled up with filling to make it against acid and alkali; this procedure is called enclosure.

Step 5: water rinsing, cleaning the radiator

Step 6: weak erosion, putting the radiator in the lye and applying weak erosion to the section that need electrodeposit in the radiator, this technique is the same as the current technique of weak erosion.

Step 7: water rinsing, cleaning the radiator

Step 8: exposure to light (acid liquor), this technique is the same as the current exposure to light technique.

Step 9: water rinsing, cleaning the radiator

Step 10: Galvanization, then conducting the first galvanization, water rinsing, zinc removal (washed with acid), water rinsing, the second galvanization, water rinsing one by one. Each technique in this procedure is the same as the corresponding current technique.

Step 11: electrodeposit with nickel-phosphorus alloy, conducting chemical electrodeposit or electrodeposit to the radiator, this technique is the same as the current nickel-electrodeposit technique. Only the section not covered by porous film on the radiator is plated with nicked and phosphor alloy, partial electrodeposit being carried out.

Step 12: post-treatment, then conducting water rinsing, drying, parching to the radiator; each technique in this step is the same as the current existing corresponding technique.

Step 13: finished products.

After the techniques in this invention, the weldable nickel and phosphor alloy is only plated in the section where the aluminum radiator or aluminum copper radiator is connected with the mainframe; the other sections are not plated with nickel and phosphor alloy. The aluminum radiator or aluminum copper radiator is only partially plated. The technique is simple and can save the nickel and phosphor alloy.

This invention's technique is based on the current technique. Before the galvanization is applied, the radiator is partially oxidized. The procedures can be simplified as: preplating 1, partial chemical oxidization 2, galvanization 3, chemical plating of nickel-phosphorus alloy, and postplating 4. Finished products.

The core technical procedures of partial chemical oxidization and enclosure can also be applied to electro-coppering, nickel electrodeposit or chemical copper plating. That is, continuing with the corresponding electro-coppering, nickel electrodeposit or chemical copper electrodeposit after the second galvanization in order to the partial electro-coppering, nickel electrodeposit or chemical copper electrodeposit to the aluminum radiator or aluminum copper radiators. It can save all kinds of expensive metals and reduce the product costs.

The above is a better implementation example of the invention. Therefore, all the equivalent changes or embellishment according to the structure, characteristics stated in the patent scope of the invention are included in the patent applicable scope of this invention. 

1. Plating, chemical plating technique using partial chemical oxidation for aluminum or aluminum copper radiator comprising the following procedures: Step 1: pretreatment to the radiator: applying degreasing, water rinsing, weak erosion by lye, water rinsing, exposure to light by washing with acid, water rinsing; Step 2: partial chemical oxidation to the radiator: immerge the part without plating of the radiator into an oxidization trough containing solution with oxidant, the part needing plating is above the solution surface to avoid oxidization, After the part is oxidized, the surface of the aluminum or aluminum copper radiator is covered with a colorless porous film; Step 3: water rinsing; Step 4: enclosure: immerge the whole radiator in an enclosed trench with water solution containing sealing compound, after the radiator is enclosed, the tin holes of the porous film on the radiator surface are filled up with sealing compound to form a film against erosion of acid or alkali on the radiator surface. Step 5: water rinsing; Step 6: weak erosion, putting the whole radiator in lye and conducting partial weak erosion to the part that need electrodeposit in the radiator; Step 7: water rinsing; Step 8: exposure to light by washing with acid liquor; Step 9: water rinsing; Step 10: galvanization: conducting galvanization, water rinsing, zinc removal by acid cleaning, second galvanization, water rinsing; Step 11: electrodeposits nickel-phosphorus alloy: conducting chemical plating or electrodeposits for the radiator, the only part not covered by porous film being plated with nickel-phosphorus alloy; Step 12: post-treatment, then conducting water rinsing, drying and parching to the radiator; Step 13: finished product.
 2. The plating, chemical plating technique of claim 1, wherein for the partial chemical oxidization in Step 2, the oxidant is organic amine including trolamine or formamine.
 3. The plating, chemical plating technique of claim 1, wherein for the partial chemical oxidization in Step 2, the solution temperature is 80-95° C., the time for oxidization is 8-30 min, the thickness of the porous film after oxidization is 0.5-5 micron.
 4. The plating, chemical plating technique of claim 1, wherein for the enclosure in Step 4, the sealing compound is boric acid.
 5. The plating, chemical plating technique of claim 1, wherein for the enclosure in Step 4, the temperature of the water solution with sealing compound is 85-95° C., the enclosure time is 8-30 min. 